Diana Rojas profiles a pair of fast-growing cities that have earned plaudits for their efforts to boost climate resilience
Mexico leads the way among Latin American countries in urban planning for climate risk, home to four out of nine cities that made CDP’s climate A-list.
In the dry desert of the state of Sonora, in the far north of the country, the capital city of Hermosillo won the CDP A-list accolade, along with Mexico City, Mérida, Ayuntamiento de Celaya, and León de los Aldama.
Last year, the city of 850,000 saw temperatures rise to 48C in June. Hermosillo is feted as one of the most liveable cities in Mexico, but strong cross-border trade with the US to the north has made it an attractive destination for internal migrants fleeing drought, unemployment, downturn in crops, and other misfortunes. With its gross domestic product (GDP) forecast to rise steeply to 2030 (133% according to the Economist Intelligence Unit) – it is struggling to accommodate rapid growth with dangerously decreasing water availability. Groundwater supplies 75% of its residents’ total needs, and there are predictions of less precipitation and even hotter days in the future.
Elevation to the A-list is recognition of Hermosillo’s efforts to manage its water resources. In 2018, Hermosillo became the first Mexican city to mandate green infrastructure design guidelines for all its public spaces, gardens, parks, alleys, rain canals and verges. The rules dictate everything from how much of a parking lot must be made up with permeable pavers (20%) to specifications for rain gardens and hydroponic green walls, to mandating that 3-5% of all new building area be permeable surface (with 50-75% of that area planted).
Hermosillo is transforming into a hub of innovation and change, committed to delivering a sustainable environment for its inhabitants
The city is also turning to new planting to preserve water reserves through its “Transform a Boulevard” partnership with 122 businesses. The companies have planted and cleaned some 24km, not only beautifying and adding shade, but using the green space to manage the scarce rain and to sequester carbon.
In addition, part of the city’s plan includes treating 100% of the wastewater produced by its residents, rendering it safe for public consumption.
In a statement to CDP, Hermosillo Mayor Célida López Cárdenas said city leaders are motivated daily by meeting people and residents who are interested in “green culture”.
“Hermosillo is transforming into a hub of innovation and change, committed to delivering a safe and sustainable environment for its inhabitants,” she said.
In Brazil, two cities made the A-list: Rio de Janeiro and Belo Horizonte. As the capital of the state of Minas Gerais, Belo Horizonte is renowned for its quality of life. The city of 2.5 million people boasts a bus rapid transit sysem, a robust Adopt a Green Space programme, bike lanes and a goal to reduce its already low greenhouse gas (GHG) emissions 20% by 2030. (Hydroelectric power in Brazil supplies nearly three-quarters of its electricity generation).
But Belo Horizonte takes clean energy up a notch: it now has some 800,000 square metres of solar collectors in the city and a system for heating water by solar energy in 3,000 buildings, more than 10 times the national average per capita. And it generates electricity by capturing methane at an old city landfill, using the biogas fuel that it produces to generate enough energy to supply 20,000 houses that consume less than 100 kilowatt hours (kWh) per month.
An A grade challenges us to be more daring and build public policies that deal with problems related to climate emergencies
The city, which endured a month of record-breaking, and deadly, rain in January, has taken steps to become more resilient in the face of climate change, with a building code that sets minimum permeable surface requirements, and other efforts to build “linear parks” to help restore the course of water throughout the city.
Net-zero is elusive because Belo Horizonte is interconnected with a national grid, and there are federal limitations on increased solar, said Dany Souza Amaral, executive secretary of the Belo Horizonte Municipal Committee on Climate Change and Eco-efficiency. But being nominated to the A-list recognises the work the city has put in to mitigate climate change since 2006, and incentivises it to forge ahead, he said.
“An A grade … challenges us to be more daring and build public policies that deal with, and also anticipate problems related to climate emergencies,” said Souza Amaral.
This article is part of our in-depth Climate-resilient cities briefing. See also:CDP green design Rio de Janeiro greenhouse gas emissions solar energy bus transit climate change eco-efficiency